text: #ifndef LATINO_BASIC_SOURCELOCATION_H
  #define LATINO_BASIC_SOURCELOCATION_H
  
  #include "latino/Basic/LLVM.h"
  #include "llvm/ADT/StringRef.h"
  #include "llvm/Support/PointerLikeTypeTraits.h"
  
  #include <cassert>
  #include <cstdint>
  #include <string>
  #include <utility>
  
  namespace llvm {
  template <typename T> struct DenseMapInfo;
  template <typename T> struct isPodLike;
  } // namespace llvm
  
  namespace latino {
  
  class SourceManager;
  
  /// An opaque identifier used by SourceManager which refers to a
  /// source file (MemoryBuffer) along with its \#include path and \#line data.
  ///
  class FileID {
    /// A mostly-opaque identifier, where 0 is "invalid", >0 is
    /// this module, and <-1 is something loaded from another module.
    int ID = 0;
  
  public:
    bool isValid() const { return ID != 0; }
    bool isInvalid() const { return ID == 0; }
  
    bool operator==(const FileID &RHS) const { return ID == RHS.ID; }
    bool operator<(const FileID &RHS) const { return ID < RHS.ID; }
    bool operator<=(const FileID &RHS) const { return ID <= RHS.ID; }
    bool operator!=(const FileID &RHS) const { return !(*this == RHS); }
    bool operator>(const FileID &RHS) const { return RHS < *this; }
    bool operator>=(const FileID &RHS) const { return RHS <= *this; }
  
    static FileID getSentinel() { return get(-1); }
    unsigned getHashValue() const { return static_cast<unsigned>(ID); }
  
  private:
    // friend class ASTWriter;
    // friend class ASTReader;
    friend class SourceManager;
  
    static FileID get(int V) {
      FileID F;
      F.ID = V;
      return F;
    }
  
    int getOpaqueValue() const { return ID; }
  }; /* FileID */
  
  /// Encodes a location in the source. The SourceManager can decode this
  /// to get at the full include stack, line and column information.
  ///
  /// Technically, a source location is simply an offset into the manager's view
  /// of the input source, which is all input buffers (including macro
  /// expansions) concatenated in an effectively arbitrary order. The manager
  /// actually maintains two blocks of input buffers. One, starting at offset
  /// 0 and growing upwards, contains all buffers from this module. The other,
  /// starting at the highest possible offset and growing downwards, contains
  /// buffers of loaded modules.
  ///
  /// In addition, one bit of SourceLocation is used for quick access to the
  /// information whether the location is in a file or a macro expansion.
  ///
  /// It is important that this type remains small. It is currently 32 bits wide.
  class SourceLocation {
    // friend class ASTReader;
    // friend class ASTWriter;
    friend class SourceManager;
  
    unsigned ID = 0;
  
    enum : unsigned { MacroIDBit = 1U << 31 };
  
  public:
    bool isFileID() const { return (ID & MacroIDBit) == 0; }
    bool isMacroID() const { return (ID & MacroIDBit) != 0; }
  
    /// Return true if this is a valid SourceLocation object.
    ///
    /// Invalid SourceLocations are often used when events have no corresponding
    /// location in the source (e.g. a diagnostic is required for a command line
    /// option).
    bool isValid() const { return ID != 0; }
    bool isInvalid() const { return ID == 0; }
  
  private:
    /// Return the offset into the manager's global input view.
    unsigned getOffset() const { return ID & ~MacroIDBit; }
  
    static SourceLocation getFileLoc(unsigned ID) {
      assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
      SourceLocation L;
      L.ID = ID;
      return L;
    }
  
    static SourceLocation getMacroLoc(unsigned ID) {
      assert((ID & MacroIDBit) == 0 && "Ran out of source locations!");
      SourceLocation L;
      L.ID = MacroIDBit | ID;
      return L;
    }
  
  public:
    /// Return a source location with the specified offset from this
    /// SourceLocation.
    SourceLocation getLocWithOffset(int Offset) const {
      assert(((getOffset() + Offset) & MacroIDBit) == 0 && "offset overflow");
      SourceLocation L;
      L.ID = ID + Offset;
      return L;
    }
  
    /// When a SourceLocation itself cannot be used, this returns
    /// an (opaque) 32-bit integer encoding for it.
    ///
    /// This should only be passed to SourceLocation::getFromRawEncoding, it
    /// should not be inspected directly.
    unsigned getRawEncoding() const { return ID; }
  
    /// Turn a raw encoding of a SourceLocation object into
    /// a real SourceLocation.
    ///
    /// \see getRawEncoding.
    static SourceLocation getFromRawEncoding(unsigned Encoding) {
      SourceLocation X;
      X.ID = Encoding;
      return X;
    }
  
    /// When a SourceLocation itself cannot be used, this returns
    /// an (opaque) pointer encoding for it.
    ///
    /// This should only be passed to SourceLocation::getFromPtrEncoding, it
    /// should not be inspected directly.
    void *getPtrEncoding() const {
      // Double cast to avoid a warning "cast to pointer from integer of different
      // size".
      return (void *)(uintptr_t)getRawEncoding();
    }
  
    /// Turn a pointer encoding of a SourceLocation object back
    /// into a real SourceLocation.
    static SourceLocation getFromPtrEncoding(const void *Encoding) {
      return getFromRawEncoding((unsigned)(uintptr_t)Encoding);
    }
  
    static bool isPairOfFileLocations(SourceLocation Start, SourceLocation End) {
      return Start.isValid() && Start.isFileID() && End.isValid() &&
             End.isFileID();
    }
  
    void print(raw_ostream &OS, const SourceManager &SM) const;
    std::string printToString(const SourceManager &SM) const;
    void dump(const SourceManager &SM) const;
  
  }; /* SourceLocation */
  
  inline bool operator==(const SourceLocation &LHS, const SourceLocation &RHS) {
    return LHS.getRawEncoding() == RHS.getRawEncoding();
  }
  
  inline bool operator!=(const SourceLocation &LHS, const SourceLocation &RHS) {
    return !(LHS == RHS);
  }
  
  inline bool operator<(const SourceLocation &LHS, const SourceLocation &RHS) {
    return LHS.getRawEncoding() < RHS.getRawEncoding();
  }
  
  /// A trivial tuple used to represent a source range.
  class SourceRange {
    SourceLocation B;
    SourceLocation E;
  
  public:
    SourceRange() = default;
    SourceRange(SourceLocation loc) : B(loc), E(loc) {}
    SourceRange(SourceLocation begin, SourceLocation end) : B(begin), E(end) {}
  
    SourceLocation getBegin() const { return B; }
    SourceLocation getEnd() const { return E; }
  
    void setBegin(SourceLocation b) { B = b; }
    void setEnd(SourceLocation e) { E = e; }
  
    bool isValid() const { return B.isValid() && E.isValid(); }
    bool isInvalid() const { return !isValid(); }
  
    bool operator==(const SourceRange &X) const { return B == X.B && E == X.E; }
  
    bool operator!=(const SourceRange &X) const { return B != X.B || E != X.E; }
  
    void print(raw_ostream &OS, const SourceManager &SM) const;
    std::string printToString(const SourceManager &SM) const;
    void dump(const SourceManager &SM) const;
  }; /* SourceRange */
  
  /// Represents a character-granular source range.
  ///
  /// The underlying SourceRange can either specify the starting/ending character
  /// of the range, or it can specify the start of the range and the start of the
  /// last token of the range (a "token range").  In the token range case, the
  /// size of the last token must be measured to determine the actual end of the
  /// range.
  class CharSourceRange {
    SourceRange Range;
    bool IsTokenRange = false;
  
  public:
    CharSourceRange() = default;
    CharSourceRange(SourceRange R, bool ITR) : Range(R), IsTokenRange(ITR) {}
  
    static CharSourceRange getTokenRange(SourceRange R) {
      return CharSourceRange(R, true);
    }
  
    static CharSourceRange getCharRange(SourceRange R) {
      return CharSourceRange(R, false);
    }
  
    static CharSourceRange getTokenRange(SourceLocation B, SourceLocation E) {
      return getTokenRange(SourceRange(B, E));
    }
  
    static CharSourceRange getCharRange(SourceLocation B, SourceLocation E) {
      return getCharRange(SourceRange(B, E));
    }
  
    /// Return true if the end of this range specifies the start of
    /// the last token.  Return false if the end of this range specifies the last
    /// character in the range.
    bool isTokenRange() const { return IsTokenRange; }
    bool isCharRange() const { return !IsTokenRange; }
  
    SourceLocation getBegin() const { return Range.getBegin(); }
    SourceLocation getEnd() const { return Range.getEnd(); }
    SourceRange getAsRange() const { return Range; }
  
    void setBegin(SourceLocation b) { Range.setBegin(b); }
    void setEnd(SourceLocation e) { Range.setEnd(e); }
    void setTokenRange(bool TR) { IsTokenRange = TR; }
  
    bool isValid() const { return Range.isValid(); }
    bool isInvalid() const { return !isValid(); }
  
  }; /* CharSourceRange */
  
  /// Represents an unpacked "presumed" location which can be presented
  /// to the user.
  ///
  /// A 'presumed' location can be modified by \#line and GNU line marker
  /// directives and is always the expansion point of a normal location.
  ///
  /// You can get a PresumedLoc from a SourceLocation with SourceManager.
  class PresumedLoc {
    const char *Filename = nullptr;
    unsigned Line, Col;
    SourceLocation IncludeLoc;
  
  public:
    PresumedLoc() = default;
    PresumedLoc(const char *FN, unsigned Ln, unsigned Co, SourceLocation IL)
        : Filename(FN), Line(Ln), Col(Co), IncludeLoc(IL) {}
  
    /// Return true if this object is invalid or uninitialized.
    ///
    /// This occurs when created with invalid source locations or when walking
    /// off the top of a \#include stack.
    bool isInvalid() const { return Filename == nullptr; }
    bool isValid() const { return Filename != nullptr; }
  
    /// Return the presumed filename of this location.
    ///
    /// This can be affected by \#line etc.
    const char *getFilename() const {
      assert(isValid());
      return Filename;
    }
  
    /// Return the presumed line number of this location.
    ///
    /// This can be affected by \#line etc.
    unsigned getLine() const {
      assert(isValid());
      return Line;
    }
  
    /// Return the presumed column number of this location.
    ///
    /// This cannot be affected by \#line, but is packaged here for convenience.
    unsigned getColumn() const {
      assert(isValid());
      return Col;
    }
  
    /// Return the presumed include location of this location.
    ///
    /// This can be affected by GNU linemarker directives.
    SourceLocation getIncludeLoc() const {
      assert(isValid());
      return IncludeLoc;
    }
  
  }; /* PresumedLoc */
  
  class FileEntry;
  
  /// A SourceLocation and its associated SourceManager.
  ///
  /// This is useful for argument passing to functions that expect both objects.
  class FullSourceLoc : public SourceLocation {
    const SourceManager *SrcMgr = nullptr;
  
  public:
    /// Creates a FullSourceLoc where isValid() returns \c false.
    FullSourceLoc() = default;
  
    explicit FullSourceLoc(SourceLocation Loc, const SourceManager &SM)
        : SourceLocation(Loc), SrcMgr(&SM) {}
  
    bool hasManager() const {
      bool hasSrcMgr = SrcMgr != nullptr;
      assert(hasSrcMgr == isValid() &&
             "FullSourceLoc has location but no manager");
      return hasSrcMgr;
    }
  
    /// \pre This FullSourceLoc has an associated SourceManager.
    const SourceManager &getManager() const {
      assert(SrcMgr && "SourceManager is NULL.");
      return *SrcMgr;
    }
  
    FileID getFileID() const;
  
    FullSourceLoc getExpansionLoc() const;
    FullSourceLoc getSpellingLoc() const;
    FullSourceLoc getFileLoc() const;
    PresumedLoc getPresumedLoc(bool UseLineDirectives = true) const;
    bool isMacroArgExpansion(FullSourceLoc *StartLoc = nullptr) const;
    FullSourceLoc getImmediateMacroCallerLoc() const;
    std::pair<FullSourceLoc, StringRef> getModuleImportLoc() const;
    unsigned getFileOffset() const;
  
    unsigned getExpansionLineNumber(bool *Invalid = nullptr) const;
    unsigned getExpansionColumnNumber(bool *Invalid = nullptr) const;
  
    unsigned getSpellingLineNumber(bool *Invalid = nullptr) const;
    unsigned getSpellingColumnNumber(bool *Invalid = nullptr) const;
  
    const char *getCharacterData(bool *Invalid = nullptr) const;
  
    unsigned getLineNumber(bool *Invalid = nullptr) const;
    unsigned getColumnNumber(bool *Invalid = nullptr) const;
  
    const FileEntry *getFileEntry() const;
  
    /// Return a StringRef to the source buffer data for the
    /// specified FileID
    StringRef getBufferData(bool *Invalid = nullptr) const;
  
    /// Decompose the specified location into a raw FileID + Offset pair.
    ///
    /// The first element is the FileID, the second is the offset from the
    /// start of the buffer of the location
    std::pair<FileID, unsigned> getDecomposedLoc() const;
  
    bool isInSystemHeader() const;
  
    /// Determines the order of 2 source locations in the translation unit.
    ///
    /// \returns true if this source location comes before 'Loc', false otherwise
    bool isBeforeInTranslationUnitThan(SourceLocation Loc) const;
  
    /// Determines the order of 2 source locations in the translation unit.
    ///
    /// \returns true if this source location comes before 'Loc', false otherwise
    bool isBeforeInTranslationUnitThan(FullSourceLoc Loc) const {
      assert(Loc.isValid());
      assert(SrcMgr == Loc.SrcMgr && "Loc comes from another SourceManager!");
      return isBeforeInTranslationUnitThan((SourceLocation)Loc);
    }
  
    /// Comparison function class, useful for sorting FullSourceLocs
    struct BeforeThanCompare {
      bool operator()(const FullSourceLoc &lhs, const FullSourceLoc &rhs) const {
        return lhs.isBeforeInTranslationUnitThan(rhs);
      }
    };
  
    /// Prints information about this FullSourceLoc to stderr.
    ///
    /// This is useful for debugging
    void dump() const;
  
    friend bool operator==(const FullSourceLoc &LHS, FullSourceLoc &RHS) {
      return LHS.getRawEncoding() == RHS.getRawEncoding() &&
             LHS.SrcMgr == RHS.SrcMgr;
    }
  
    friend bool operator!=(const FullSourceLoc &LHS, FullSourceLoc &RHS) {
      return !(LHS == RHS);
    }
  
  }; /* FullSourceLocation */
  
  } // namespace latino
  
  namespace llvm {
  /// Define DenseMapInfo so that FileID's can be used as keys in DenseMap and
  /// DenseSets
  template <> struct DenseMapInfo<latino::FileID> {
    static latino::FileID getEmptyKey() { return {}; }
  
    static latino::FileID getTombstoneKey() {
      return latino::FileID::getSentinel();
    }
  
    static unsigned getHashValue(latino::FileID S) { return S.getHashValue(); }
  
    static bool isEqual(latino::FileID LHS, latino::FileID RHS) {
      return LHS == RHS;
    }
  };
  
  template <> struct isPodLike<latino::SourceLocation> {
    static const bool value = true;
  };
  template <> struct isPodLike<latino::FileID> {
    static const bool value = true;
  };
  
  // Teach SmallPtrSet how to handle SourceLocation
  template <> struct PointerLikeTypeTraits<latino::SourceLocation> {
    enum { NumLowBitsAvailable = 0 };
  
    static void *getAsVoidPointer(latino::SourceLocation L) {
      return L.getPtrEncoding();
    }
  
    static latino::SourceLocation getFromVoidPointer(void *P) {
      return latino::SourceLocation::getFromRawEncoding((unsigned)(uintptr_t)P);
    }
  };
  
  } /* namespace llvm */
  
  #endif
  